Intake silencer for internal-combustion engines



Sept. 18 1923. l,468,398

J. REED INTAKE SILENCER FOR INTERNAL COMBUSTIONENGINES Original FiledMay 6, 1921 Patented Sep't. 18, 1923.

UNITED sr rEs 1,468398 PATENT OFFICE;

JOHN BEED, OF COBBBIDGE-ON-TYNE, ENGLAND.

INTAKE SILENCER FOB. INTERNAL-COMBUSTION ENGIN'ES.

Original application filed lay 8, 1921, Serial '100. &67,484. Dividedand tli application filed November 21, 1 922. Serial Io. 602418.

To all 'whom it may concern: i

Be it known that I, JOHN REED, a subject of the King of Great Britain,residin at 'Corbridge House,` Corbridge -on yne, Northumberland,England, have invented certain new and useful Improvements in IntakeSilencers for Internal-Combustion Engines, of which'the'following is aspecification.

'The present invention is a division of my patent application Serial No.467484 filed.

Gth May, 1921, relating to silencing devices for rapidly fiowing gases.i

The object of the present, invention is to provide an improved silencingdevice of simple Construction whereby noises -caused by gases or airentering a chamber will be entirely obviated or so much minimized as tobe negligible. The silencing device according to this invention and ashereafter described is particularly applicable for use with internalcombustion engines, and may be connected, for instance, to thecarburettor of an internal combustion engine for the purpose ofpreventing the hissing noise caused b the infiowing air thereto.

Accor ing to this inventio an elongated enter casing of substantiallyequal diameter throughout its length is constructed having an openendedtube entering at one end and extending to near the opposite closed endof the outer casing, the sa-d open-ended tube having series of holesformed in'its wall within thecasing, the holes towards the in ner end ofthe tube being larger in rea than the holes towards the enterng end ofthe tube; 'or alternatively the tube within the casing may be formedwith a slot or slots which increase in area as they approach theinnerend of the said tube. The outer casing is forined with an openingor provided with a tube connunicatng with the outer' casing adjacent tothe entrance end of the aforesaid open-ended tube having the slots orholes.

In the a paratus above generally outlned accor ing to the presentinvention, hen entering gases are being dealt with s r instance whendealing with air passng o -a carburettor, the air ,may enter rough theexterior open end of the tube ving the graduated apertures or slots andss to the carbnrettor by the opening or extending from the outer casing,or the 'j course may be reversed, that is the air may enter the outercasing through the' opening or ppe co'nmuncating therewith and may passto the carburettor through the tube having the graduated apertures orslots.

The invention will be further described with reference to the examplesof Construction shown on the accompanying drawings.-

the passage of the air current is reversed,-

that is the air passes into the outer casing through an aperture andfinds its exit therefrom to the carburettor b the open-ended tube havingthe graduate slot or perfora-` t'ons.

The silencer in accordance with this invention as shown at Fig. 1 isdesigned for use in conjunction with the carburettor of an internalcombustion engine,' the closed 'casng 1 being cylindrical in shape andformed.with an outlet pipe 6 near one end suitable for connection withthe carburettor of the engine.

Through an opening in one end of the cylindrical chamber 1 and adjacentto the outlet pipe 6, &tube 4: is inserted. This tube 4, which is openat both ends, extends within the casng 1 to within a short distance ofthe opposite end of the .casing and forms the inlet for air passing tothe carburettor. The wall of, this tube 4 within the casing is forniedwith a slot 5 extending from 'its inner open end for a portion of itslength the said slot increasing in area as it approaches .the said inneropen'end, and the outer end of the said tube outside the casing 1 isformed with a bell mouth.

The air enters the casing through the bell mouth of the slotted tubeandfinds its way partly through the graduated slot (or it may be series ofholes) and partly through' the open inner end of the tube 4; to theoutlet pipe 6 which is connected to the carburettor. The 'entering airin passing down the slotted tube 4 will pass through the slot 5 thereinin g'adually increasing quantities and through the end of the said tube4 to the carburettor. I

The sound Vibrations reaching the outer air, travel in the reversedirection to the entering air. As each vibration enters the slencer fromthe carburettor it travcls down the casing 1 of the silencer and as itdoes so it gradually escapes into the slotted tube 4 through the openslot 5 until it reaches the inner open end of the tube 4 when theremainder escapes through said tube 4 to the outer air. It will be seenthat part of the Vibration escepes immediately to the open air throughthe small end of the slot 5 whilst the remainder has to travel varyingdistances up to twice the length of the slot 5 before eseaping, that isonce up inside the casing to 'the end of the slot and back inside theinner tube. The vibrations are therefore spread out over a long periodof time and thus noise is prevented. The frequency of the vihrations isvery great, but by this invention with quite& short silencer it ispossible to extend the time of each Vihration until it overlaps thesucceeding one and thus obtain almost absolute silence.

Obviously the gases passing to the engine by way of the device, ma beoeused to pass in the direction describe or in the opposite direction ifdesired.

To suit certain conditions and .as shown et Figs. 2 and 3 a modifiedConstruction of the silencer may he desirahle consisting of ecylindrical casng 1 open at one end 9 and closed at the othen A tube 4:extends within the seid casing 1 supported by radial arms 10 Fig. 3,within .the open end of the casing i, the outer end of the said tube 4being connectcd to the air inlet of the carburettor of the engine. Theinwardly projecting tube 4 is slotted or performed as before described.

lVith this Construction air will enter the open'end 9 of the casing lbetween the ra diel arms 10 supporting the inner slotted or perforatedtube e and find its way to the earhurettor, entering partly through theslots or perforations 5 and partly through the iniier open end of thesaid tube 4.

The siencing action is the same es in the previous example.

Yv'het l claim as my invention and dcsire to secure by Letters Patentis: i

1. In e device for silencing repidly flowing gases entering an internalcombustion engine, an elongated outer cesing of substantiaily uniformdiameter throughout its length, one end of which casing is closed andthe other end in communication with the induction pipe of the engine, incombi nation with a tube trzversing neni-ly the whole length of saidcesing, said tube being at one end open to the atmosphere and at theother end open to the interier of said casing adjacent the closed endthereo'f, and said tube being formed with :1 slot, which slot increasesin width as it approaches the inner end of said tube.

2 In a device -for silencing rapidly flowing gases entering an internalcombustiou engine, an elongated cylindrical outer casing ofsubstantielly uniform diameter throughout its length, one end of whichcasing is 'closed and the other end in communication with the inductionpipe of the engine, in combination with a tube treversing nearly thewhole length of said casing seid tube being at one end open 'to theatniosphere and at the other end open to the interier of said casingadjecent the closed end thereof, und said tube being formed with a slotwhich slot increases in width es it approaches the inner end of saidtube.

. 3. In a device for silencing rapidly flowng gases entering :ininternal eombustiou engine, an elongnted outer cnsing ot' suhstantiallyuniforn diameter throughout li& length, one end of which casing isclosed and the other end in communication with the induotion pipe of theengine, in combinetion 'with e tuhe traversin neni-ly the whole lengthof seid cusing, said tube Being :it one end hell-mouthed and open to theatmosphere and at the other end open to the interior of said cesingadjecent the closed end thereof, and said 'tube being 'formed with aslot, which slot increases in width as it ;ipproeches the inner end ofsaid tuhe.

In witness whereof I here hereunto set my hand in the presence of twowitnesses.

JOHN REED.

witnesses:

FEARLEE lViNsHIP,

CISSY NIooLsoN.

